<VV> Part throttle surging

[Bryan Blackwell]

Hi folks,

Good to see the Vair Fair attendees had a good event this year, I had commitments for Saturday and couldn't make it.

Sunday we took the '66 Corsa (basement '66 110, not a 140) to the Mazda club autocross - Trevor took the '99 Miata.  With her fluorescent green plasti dip "paint job" and white 16" wheels, we were something of party crashers amongst the (mostly) imports.  I ran not too awful times and ended up 20th out of 27 on a course that might be described as "cozy".  The car ran nicely, didn't break, and got back home without any real trouble.

But I do have an issue I'd like to track down.  It starts right up, idles fine, has good power in all gears and pulls nicely out on the highway.  But at all speeds and gears if you're just driving at partial throttle, it has this annoying surge.  It's like you're just slightly on and off the throttle.  The car also gets kind of lousy mileage for a Corvair, upper teens.  I recently replaced the vac advance can because it wasn't advancing and that improved the mileage a few mpg but it didn't make any difference to the way it drives.

Engine is a stock '66 110, the only mods are a set of relocated jet '66 carbs with 51 jets and a Crane X-700 ignition (no points).  It has good compression and not too many miles on the plugs and wires.  Transaxle is a '65 4speed/3.55:1

One final note - if you're looking for summer performance tires that might see an occasional autocross, I'm very happy with BFG's gForce Sport COMP2, they handle rain well, ride decently, and have pretty good grip.  They will *not* work in any kind of freezing/frozen precip, however.


Bryan Blackwell | Springfield, Va. | bryan at skiblack.com | http://autoxer.skiblack.com/  
  Corvairs: '62 700 Wagon, '64 Greenbrier, '65 Corsa, '66 Corsa
  '69 Road Runner, '99 Neon R/T, '00 Miata SE, '09 Ford F-150
"Why do something if you're not going to obsess about it?"